Britain is working with Sierra Leone to coordinate rescue efforts for victims of "devastating" mudslides and torrential flooding which have killed hundreds of people.
International Development Secretary Priti Patel said the UK also stands ready to provide further assistance, with many victims trapped in homes buried under tonnes of mud.
More than 300 people are reported to have died following the mudslides in and around the capital Freetown, with the number expected to rise.
The Red Cross estimates 600 people are missing and 3,000 people have been left homeless by the disaster, while communications and electricity supply have also been affected.
Aid agency Save the Children said a member of staff and his young children are among the missing after their house was buried during Monday's mudslide.
Ms Patel said: "I am deeply saddened by the devastating landslides and flooding in Freetown, Sierra Leone, which have claimed innocent lives.
"My thoughts are with all those affected at this tragic time.
"From stopping the Ebola outbreak in its tracks to helping the country rebuild after this deadly disease, the UK continues to stand by the people of Sierra Leone.
"We have pre-positioned vital aid supplies and helped prepare the country's response to disasters.
"We are already working with the government of Sierra Leone to coordinate the rescue efforts and are ready to provide further assistance to those in need."